
Dl
DAUNTLESS
V-6
ENGINE
In
addition to the instructions covering operations
for disassembling the
engine
out of the vehicle, special instructions are given to cover different
operations required when disassembly is
done
with
the
engine
installed.
During
disassembly operations, the
engine
should be mounted in a suitable
engine
repair stand.
Where
practicable, modify or adapt an existing re
pair
stand as necessary to accommodate the
engine.
If
an
engine
repair stand is not used, take care to
perform
disassembly operations in a manner that
will
protect personnel against an accident and the
engine
and its parts against damage.
Dl-6.
Mounting Engine
On
Engine Stand
Refer
to Fig. Dl-4.
a.
With
the
engine
supported by a hoist, remove
the clutch housing and clutch. Match
mark
the flywheel and the clutch cover before disassembly to assure proper reassembly.
b. Position the
engine
on the
engine
stand.
c. Release
some
tension of the hoist cables and secure
engine
to stand.
d.
Make sure the position lock on the
engine
stand
is tight to prevent the
engine
from accidentally
inverting.
e.
Release the hoist cables.
FIG.
D1
-4—ENGINE
MOUNTED
ON
STAND
1—
Spacer
J-8690-6
A—Bolt,
i/2-NC
x 3i/2"
2—
Bolt,
3/a-NC
x 4*/2" 5—Adapter 21316-J 3—
Engine
Mounting Stand
Dl-7.
Remove Intake Manifold
and
Carburetor Assembly
Disconnect crankcase vent
hose,
distributor vacuum
hose,
and fuel line from carburetor. Disconnect two distributor leads from ignition coil. Disconnect
wiring
harness from coolant temperature sending
unit.
Remove ten cap
bolts
which attach intake
manifold to cylinder heads. Remove intake mani
fold assembly and gaskets from
engine.
Dl-8. Remove Exhaust Manifold
The
engine
has two exhaust manifolds. Remove five attaching screws, one nut, and exhaust mani
fold from each cylinder head.
Dl-9.
Remove Distributor
Disconnect vacuum
hose
and wiring harness from
distributor.
Disconnect spark plug cables from
spark
plugs. Remove sparks plugs from
engine.
Pull
spark
plug cable retainers from brackets on rocker
arm
covers. Remove mounting screw, retainer
bracket,
and distributor from timing chain cover.
If
timing chain and sprockets are not to be re
moved from
engine,
note
position of distributor
rotor so that it can be installed in identical position.
Dl-10. Remove
Fuel Pump
Disconnect output fuel line from fuel pump. Re
move
two mounting bolts, fuel pump, and gasket
from
timing chain cover.
Dl-11.
Remove Alternator
and Fan
Belt
Disconnect wiring harness from alternator. Remove nut and flat washer which fasten alternator to
adjustment bracket. Pivot alternator
inward,
to
ward
engine
cylinder block, to relieve fan belt
tension. Remove fan belt from pulleys. Remove
two attaching screws, mounting bracket, and alter nator from right cylinder head of
engine.
Dl-12.
Remove Cooling
Fan and
Water Pump
Refer
to Fig. Dl-5.
Remove four cap screws, lock washers, cooling fan,
fan
hub, and fan drive pulley from flange of water
pump shaft. Remove nine attaching screws, water
pump, alternator adjustment bracket, and water pump from timing chain cover.
Dl-13.
Remove
Oil
Filter
Unscrew
oil filter from
engine
oil pump.
Dl-14.
Remove Starter Motor
Disconnect wiring harness from starter motor and
solenoid. Remove two attaching screws, starter motor, solenoid, and motor attaching bracket from
engine
flywheel housing and cylinder block.
Dl-15.
Remove
Oil
Pressure Sending Unit
Disconnect wiring harness from oil pressure send
ing unit. Remove oil pressure sending unit from
engine
cylinder block.
Dl-16.
Remove
Oil
Dipstick
Withdraw
and remove oil level dipstick and dip
stick
tube
from
engine
cylinder block.
Dl-17.
Remove Crankshaft Pulley
Remove six attaching screws and crankshaft pulley
from
crankshaft vibration damper. 80

Dl
DAUNTLESS
V-6
ENGINE
e.
Connect electrical wiring harness to coolant
temperature sending unit. Connect two distributor leads to ignition coil. Connect fuel line
between
fuel pump and carburetor, vacuum
hose
between
distributor and carburetor, and crankcase vent
hose
to intake manifold
below
rear
of carburetor.
FIG.
D1-46—-INTAKE
MANIFOLD
INSTALLATION
1—Long Bolt 2—Open Bolt Hole
Dl-102.
ENGINE INSTALLATION
Install
the
engine
in the vehicle in the following
procedure listed
below:
a.
Attach suitable sling to
engine
lifting
eyes
and,
using a hoist, lift the
engine
from blocks or
engine
stand.
b. When
engine
is free of the stand lower it slowly
into
the
engine
compartment of the vehicle.
Note:
The
engine
and transmission must be lined
up to
engage
the main shaft and clutch plate spline
while sliding the
engine
rearward
into
the mounting
position.
c.
Install
and tighten up
bolts
securing
engine
to
flywheel housing.
d.
Install
and tighten front
engine
mounting bolts.
e.
Remove sling from the
engine.
I.
Connect exhaust pipes to right and
left
engine
manifolds.
g. Connect choke cable support bracket to
car
buretor.
h.
Connect
engine
fuel
hoses
and fuel lines at right
frame
rail.
I.
Connect fuel lines.
j.
Mount
engine
starter motor assembly to
engine.
k.
Connect battery cable and wiring to
engine
starter
motor.
I.
Connect
engine
wiring harnesses to connectors
located on
engine
firewall.
Note:
On
engines
equipped with exhaust emission
control, replace the air pump, air distributor mani
fold, and anti-backfire (gulp) valve. See Section F2.
m. Replace radiator, and secure with bolts,
n.
Replace and tighten right and
left
radiator sup
port rods.
0. Connect upper and lower radiator
hoses
to the
engine.
p. Connect alternator wiring harness from connec
tor at regulator,
q.
Replace air cleaner.
r.
Connect battery ground cable from the battery
to the
engine
and the
engine
ground strap,
s.
Replace the hood.
After
the
engine
is installed in the vehicle,
fill
radiator
with coolant and
engine
with oil (Refer to
Lubrication
Section B), then perform an
engine
Tune-up
and road
test
(Refer to Tune-up Sec
tion C).
Dl-103.
FINAL IN-VEHICLE ADJUSTMENTS
a.
Clean
battery terminals and check battery.
b.
Check
ignition wires and connections.
c. Service carburetor air cleaner.
d.
Service positive crankcase ventilation valve.
e.
Check
fuel lines.
f. Gap and install new
spark
plugs.
g.
Check
distributor
points
and capacitor; replace
if
necessary.
h.
Check
ignition (distributor) timing; reset if
necessary. 1.
Check
carburetor adjustments; reset if necessary,
j.
With
engine
fully warmed up, tighten cylinder
head and manifold
bolts
and nuts to specified
torque.
Check
cylinder head
gaskets
and
bolts
for
air
or coolant leaks.
Note:
Tightness of cylinder head
bolts
should be
checked and corrected after 500 miles [800 km.]
of normal operation and again at 1000 miles [1600
km.].
k.
Check
fan belt tension; adjust if necessary.
I.
Check
for and correct any oil leak, fuel leak or
coolant leak. 104

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL
COOLING
SYSTEM
Contents
SUBJECT
PAR.
GENERAL
.G-l Antifreeze Solutions. .G-l6
Cylinder
Block.
..................
.G-8
Draining
Cooling System............... G-3
Engine
Overheating..
.................
.G-19
Fan
Belt.
......... .........
.G-18
Filling
Cooling System.................
G-2
Inhibited
Coolant Solution .G-l7
Temperature
Sending Unit.
...........
.G-l0
Thermostat
.........................
G-9
RADIATOR
.G-5
Radiator
and Heater Hoses.............
G-7
SUBJECT
PAR.
Radiator
Pressure
Cap.................
G-4
Radiator
Removal and Replacement..... G-6
WATER
PUMP.
. . .G-ll
Water
Pump Disassembly. .............G-13
Water
Pump Inspection.
..............
.G-12
Water
Pump Reassembly.
.............
.G-14
Water
Pump Removal and Replacement. .G-l5
SERVICE
DIAGNOSIS.
.G-20
SPECIFICATIONS
. .G-21
ANTIFREEZE
CHART.
..... ... .G-22
G-l. GENERAL
a.
The satisfactory performance of the Hurricane
F4
engine
is controlled to a great
extent
by the proper operation of the cooling system. The
engine
block is full length water jacketed which prevents
distortion of the cylinder walls. Directed cooling
and
large water holes, properly placed in the cylin
der head gasket cause more water to flow past the
valve
seats
(which are the
hottest
parts of the
block)
and
carry
the heat away from the valves, giving positive cooling of valves and seats.
Minimum
temperature of the coolant is controlled by a thermostat mounted in the
outlet
passage of
the engine. When the coolant temperature is below
thermostat-rated temperature, the thermostat re mains closed and the coolant is directed through
the radiator-bypass
hose
to the water pump. When the thermostat opens, coolant flow is directed to
the top of the radiator. The radiator dissipates the
excess
engine
heat before the coolant is recirculated
through the engine.
The
cooling system is pressurized. Operating pres
sure
is regulated by the rating of the radiator cap
which
contains a relief valve, b. The Dauntless V-6
engine
efficiency and performance is controlled to a great
extent
by proper
operation of the cooling system. The cooling system
does
more than cool the engine. It also directs
the flow of coolant to provide the
best
operating
temperature range for each part of the engine.
In
the Dauntless V-6
engine
coolant is forced by
the water pump into two main passages that run the length of the block on each side (Fig. G-l).
FIG.
G-1—COOLANT
FLOW
THROUGH
THE
DAUNTLESS
V-6
ENGINE
161

COOLING
SYSTEM
14263
FIG.
G-2—COOLING SYSTEM
COMPONENTS
V-6
ENGINE
1—
Radiator
Pressure Cap
2—
Hose
Clamp
3—
Radiator
Hose (Inlet-Upper)
4—
Radiator
Hose (Outlet-Lower) 5—
Bolt
6—
Water
Pump Assembly 7—
Cap
8—Thermostat
By-Pass Hose
g—Water Outlet
Elbow
10—
Gasket
11—
Thermostat
12—
Water
Pump Gasket
13—
Dowel
Pin
14—
Radiator
Shroud (Heavy Duty Cooling) 15—
Pulley
16—
Fan
Spacer
17—
Fan
and Alternator Belt
18—Fan
19—
Lockwasher
20—
Radiator
21—
Drain
Cock
From
these
main passages, the coolant flows around
the
full
length of each combustion chamber.
After
cooling the block, the coolant passes through
ports between the block and each cylinder head.
These
ports direct most of the coolant flow around the exhaust valve area to prevent hot exhaust
gases
from
overheating the exhaust ports.
From
the cylinder heads, the water passes into a
water
manifold between each of the heads and the
water
pump. If the thermostat is closed, the coolant
is ported back to the pump where it is recirculated
back
into the pump and into the engine. After the
coolant heats enough to open the thermostat, the coolant is directed from the water manifold through
a
hose
to the top of the radiator and then through
the radiator which acts as a heat exchanger to cool the fluid. The coolant is then ported through a
hose
from
the bottom of the radiator to the pump, which
recirculates
it back to the engine.
The
cooling system is pressurized. Operating pres
sure
is regulated by a relief valve in the radiator
cap. The
heater inlet
hose
is connected to a port on
the right bank cylinder head. The outlet
hose
is connected to the heater adapter tube on the water
pump.
c.
It is recommended when using water for coolant
that the cooling system be flushed and checked for leaks twice a year, preferably in the
fall
before
antifreeze is added and in the spring when the antifreeze is drained.
Reverse
flushing
will
aid greatly in removing rust 162

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL
G and
scale, especially when used with a flushing
solution. A cleaning solution should be used to
loosen
the rust and scale before reverse flushing
the cooling system.
Flushing
is accomplished through the system in a direction
opposite
to the normal coolant flow.
This
action causes the water to get behind the corrosion
deposits
and force them out. To do this, remove
the upper and lower radiator
hoses.
Then
attach a
drain
hose
at the top of the radiator. Attach a new
piece of
hose
to the radiator
outlet
at the
bottom
and
insert the flushing gun. Connect the water
hose
to the flushing gun to a water
outlet
and the air
hose
to an air line.
Turn
on the water and when
the radiator is
full,
apply the air in short blasts,
allowing the radiator to
fill
between
blasts.
Con
tinue this flushing operation until the water runs
clear
through the top
hose.
With
the thermostat removed, attach a leadaway
hose
to the water
hose
inlet. Also attach a length
of new
hose
to the water
outlet
connection at the
top of the engine.
Turn
the water on and
fill
the
water jacket and then apply air in short blasts.
Continue
this flushing until the water runs clear.
Also
do the hot water heater. Remove heater water
outlet
hose
from heater core. Remove inlet from 163

G
COOLING SYSTEM
engine
connections. Insert flushing gun and flush
heater core.
Care
must be taken when applying air
pressure to prevent damage to the heater core.
G-2.
Filling
Cooling System
To
fill
the cooling system, remove the
fill
cap and
fill
the tank to the top. Replace the cap and run
the
engine
at medium speed for approximately one
minute. Remove the cap and recheck the coolant level. Add more coolant if necessary to bring the level back to the top of the tank. If the cooling system is filled when the
engine
is cold, recheck the coolant level after the
engine
has warmed up.
This
will
ensure that the thermostat has opened allow ing complete cooling system circulation.
Always
correct any cooling system leaks before installing antifreeze. A corrosion inhibitor should be used in the cooling system to prevent the forma
tion of rust and scale. A quality brand antifreeze containing a corrosion inhibitor should be used.
When
the antifreeze is drained in the spring, a
corrosion inhibitor should be added with the water.
Note:
Cooling system components for both V6 and
F4
engines
are shown in
Figs.
G-2 and G-3.
G-3. Draining
Cooling System
To
completely
drain
the cooling system, open the
drain
in the
bottom
of the radiator and also a
drain
on the right side of the cylinder block on the
Hurricane
F4 engine. The Dauntless V-6
engine
has two
drain
plugs, one located on each side of the cylinder block. Both plugs must be removed to
completely
drain
the cooling system.
Remove the radiator cap to break any vacuum
that may have developed.
Should
the cooling solution be lost from the system
and
the
engine
become
overheated do not
refill
the system immediately but allow the
engine
to cool or
refill
slowly while the
engine
is running. If
cold solution is poured into the radiator while the
engine
is overheated there is danger of cracking the
cylinder
block and/or cylinder head.
G-4.
Radiator Pressure
Cap
All
radiators are equipped with pressure caps which
reduce evaporation of cooling solution and make the
engines
more efficient by permitting slightly
higher operating temperatures. When operating
properly,
the pressure cap permits pressure build-up
in
the cooling system during periods of severe heat
load.
This
pressure increases the boiling point of the coolant and thus reduces overflow losses. The
effectiveness
of the cap is limited by its opening
pressure and the boiling point of the coolant (see
note
below). The pressure cap employs a spring-
loaded, rubber-faced pressure seal which presses against a seat in the radiator top tank. Spring pres
sure
determines the opening pressure of the valve.
A
typical pressure cap is shown in Fig. G-5.
Note:
Refer to cooling system specifications (Par.
G-21)
for opening (relief) pressure when the ve
hicle is equipped with either the
Hurricane
F4
or
Dauntless V-6 engine. If a new cap is required, always install a cap of the same type and pressure
rating
specified. It should never be altered or re
placed by a plain cap.
A
vacuum release valve (Fig. G-5) is employed to
prevent undesirable vacuum build-up when the system
cools
down. The vacuum release valve is
held against its seat under light spring pressure.
Vacuum
in the system is relieved by the valve
which
opens
at V2 to 1 psi. [0,035 a 0,07 kg-cm2]
vacuum.
A pressure tester can be used to check and
test
the vacuum pressure rate (see Fig. G-6).
Although the mechanism of the pressure cap re quires no maintenance, the cap should be inspected
periodically for cleanliness and freedom of opera tion. The pressure cap gasket and radiator filler neck seat should also be inspected to be sure they
are
providing a proper seal. If the rubber face of
the valve is defective, a new cap should be installed.
Filler
neck reseating
tools
are commercially
avail
able to correct minor
defects
at the surface of the seat. Follow instructions of the reseating tool manu
facturer.
To
remove the radiator pressure cap when the
engine
coolant temperature is high or boiling, place
a
cloth over the pressure cap and
turn
counter clockwise about Vi
turn
until the first (pressure release)
stop
is reached. Keep the cap in this posi
tion until all pressure is released.
Then
push cap
down and
turn
still
further until cap can be re moved. To install the pressure cap, place it in posi
tion and
turn
it clockwise as far as it
will
go.
Caution:
Use extreme care in removing the radiator
pressure cap. In overheated systems, the sudden release of pressure can cause a steam flash and this
flash,
or the
loosened
cap can cause serious personal
injury.
G-5.
RADIATOR
Maintenance of the radiator consists of keeping
the exterior of the radiator core clean, the interior free from rust and scale, and the radiator free from
leaks.
Check
the cooling system fluid level and for
leaks each
2000
miles
[3.200
km.] or every 30
days, whichever occurs first.
This
exterior of the
radiator
core should be cleaned and the radiator inspected for leaks each
6000
miles
[9.600
km.]
of normal service of the vehicle. Cleaning should be performed by blowing out with air stream or water stream directed from the
rear
of the radiator.
Visual
inspection is not sufficient as the accumula tion of small particles of foreign material on core
surfaces can restrict cooling without closing the core openings.
Radiator
leakage occasionally results from cor
rosion perforation of the metal but most leakage results from mechanical failure of soldered joints
when too much strain has been put on the joint.
Fractures
occur most
often
at the joint where the
radiator
inlet and
outlet
pipes are attached to the
tanks.
When the seams break, the entire soldered
joint
is
exposed
and can corrode, but breakage
rather
than corrosion is the
primary
cause of seam
leakage. Examine the radiator carefully for leaks before and after cleaning. Cleaning may uncover points of leakage already existing but plugged with
rust.
White, rusty, or colored leakage stains indicate 164

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL
G
FIG.
G-4—PRESSURE TESTING COOLING SYSTEM
1—Pressure Tester C-3499 previous radiator leakage. These
spots
may not be
damp if water only or methyl-alcohol-base anti freeze is in the cooling system since such coolants
evaporate readily. An ethylene-glycol-base anti freeze shows up existing leaks as it
does
not evapo
rate.
The radiator may be tested for leaks by using
a
Pressure Tester Tool C-4080, as shown in Fig.
G-2.
When
the pressure cap opens, the sudden surge of
vapor
or liquid must blow out through the overflow
pipe. If the overflow pipe is dented or clogged,
the pressure caused by obstruction may cause dam
age to the radiator or
hose
connections in the cool-
1
FIG.
G-5—RADIATOR PRESSURE
CAP
1—
Pressure
Cap
2—
Overflow
Tube
3—
Pressure
Seal 4—
Vacuum
Release Valve
5—
Radiator
Neck
FIG.
G-6—TESTING RADIATOR PRESSURE
CAP
1—
Radiator
Pressure Cap
2—
Adapter
3—
Pressure
Tester C-3499 ing system. To remove clogging material, run a
flexible wire through the overflow pipe.
G-6.
Radiator Removal
and
Replacement
a.
Drain
the radiator by opening the
drain
cock
and
removing the radiator pressure cap.
b.
Remove the upper and lower
hose
clamps and
hoses
at the radiator.
c.
Remove the four cap screws, lock washers and
flat washers that secure the radiator to the radiator
body support. Remove the radiator.
d.
To replace the radiator, reverse the removal
procedure.
G-7.
Radiator
Hoses
and
Heater Hoses
Air,
heat, and water deteriorate radiator and heater
hoses
in two ways: by hardening or cracking which
destroys flexibility and causes leaks; by softening
and
swelling which produces lining failure and
hose
rupture
and clogging. Examine
hoses
spring and
fall
for possible need of replacement or tightening.
If
hoses
are collapsed, cracked, or indicate a
soft
condition on the inside they should be replaced.
Correct
installation of a new heater
hose
is impor
tant to prevent contact between the
hose
and the
exhaust manifold. On the
Hurricane
F4 engine the
molded curved end of the
hose
connects to the
hot water intake of the heater; the flexible end to the hot water valve on top of the cylinder head.
On
the Dauntless V-6 engine the heater inlet
hose
is connected to the
rear
of the intake manifold 165

G
COOLING SYSTEM and
the outlet
hose
is connected to the water pump
housing.
When
installing a new hose, clean the pipe connec
tions and apply a thin layer of nonhardening seal
ing compound. Hose clamps should be properly
located over the connections to provide secure fastening. The pressurized cooling system pressure
can
blow off improperly installed hoses.
G-8.
Cylinder
Block
Any
coolant leaks at the engine block water joints
are
aggravated by pump pressure in the water
jacket
and by pressure developed in the cooling system when the pressure cap is in place.
Small
leaks showing up only as moist
spots
often
cannot
be detected when the engine is hot except by the
appearance of rust, corrosion, and dye stains where
leakage evaporated. Also, expansion and contrac tion of the engine block resulting from extreme
temperature changes can aggravate leaks. For
these
reasons, when checking for coolant leaks inspect
the block when it is cold and while the engine is
running.
A
leaking
drain
cock or plug that cannot be stopped
leaking
by tightening should be replaced.
Leaking
core-hole expansion plugs should be replaced.
If
tightening gasketed joints
will
not correct leak
age, install new gaskets. Use a sealing compound
where recommended.
G-9.
Thermostat
a.
The cooling system of the engine is designed
to provide adequate cooling under most adverse conditions. However, it is necessary to employ
some
device to provide quick warming and to prevent
overcooling during normal operation. Automatic
control
of engine operating temperature is provided
by a water flow control thermostat installed in the
water
outlet of the
Hurricane
F4 engine. The ther
mostat is a heat-operated valve. It should always
be maintained in working order and the vehicle
should never be driven without one installed as there would then be no control of engine tempera
ture.
The temperature at which the thermostat
opens
is preset and cannot be altered.
b.
The thermostat on the
Hurricane
F4 engine is
located in a housing on the top front of the cylinder
head.
On the Dauntless V-6 engine it is located
in
the thermostat housing of the air intake manifold.
The
standard engine thermostat for the
Hurricane
F4
and Dauntless V-6 engine has a normal rating
of
190°F.
[87.8°C]
and should begin to open at
a
coolant temperature between
180°F.
[82°C]
to
192°F.
[89°C]
and be fully open at
202°F.
[94°C.].
See Fig. G-7 for method of testing.
When
the thermostat is not operating properly, the engine may
run
too hot or too cold. Overheating
may
damage the thermostat so that its valve
will
not function properly, and a cold engine
will
not achieve
full
efficiency.
Rust
can also interfere with
thermostat operation. To
test
the thermostat, place
it
in water heated approximately
25°F.
[17°C]
above the temperature stamped on the thermostat
valve.
Submerge the bellows completely and agitate
the water thoroughly. The valve should open fully.
Next, place the thermostat in water heated approxi-
FIG.
G-7—THERMOSTAT
TEST
mately 10°F.
[11°C]
below the temperature
stamped on the thermostat valve. Submerge the bellows completely and agitate the water thorough
ly.
The valve should close completely. If the ther
mostat fails either of
these
tests, it should be re placed with a new one of the same type and rating.
G-10. Temperature
Sending Unit
The
sending unit incorporates a temperature sens ing element that when it is surrounded by cold engine coolant, the unit provides the highest resist
ance in the temperature
gauge
indicator
circuit.
Resultant
low current flow in the circuit causes the
indicator
on the instrument panel to read at the low (C) end of the
gauge.
As engine coolant tem
perature
increases, the resistance of the unit is
decreased allowing an increased current flow in
the
circuit,
making the instrument panel
gauge
register in proportion to the temperature of the engine coolant.
To
test
the sending unit, first run the engine until
it
has had time enough to warm up.
If
no reading is indicated on the
gauge,
check the
sending unit to
gauge
wire by removing the wire
from
the sending unit and momentarily grounding
the wire. If the
gauge
now indicates, the sending
unit
is faulty. If the
gauge
still
does
not indicate, the wire is defective.
Repair
or replace the wire,
a.
Hurricane
F4 Engine.
The
thermo-couple coolant temperature sending
unit
is mounted in the right
rear
of the cylinder head (Fig. G-8) and is connected by a single wire
to the dash unit of the instrument cluster. 166